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I have seen and used almost every single commercially available micron gauge. Bluevac and JB(69075) do well and so does Inficon. All of them loose accuracy over time and none of them can accurately measure the full range from Atmosphere to deep vacuum. The only gauges that accurately and reliably measure the full range for extended periods of use are the big money bench top ones for lab use and they wouldn't survive in the field.

What you need to know about whatever gauge you use is this. What is the actual range of the sensor? Commercial micron gauges have sensors designed to start reading vacuum only under a certain level. That level could be 20,000 microns 15,000 micron 5,000 micron or even as low as 1,500 microns. Everything the gauge shows you above that is only an estimate and not based on the sensors designed capabilities. If your not sure where you gauge sensors range is, contact the manufacturer or their rep. This piece of information is crucial to using any micron gauge.

My recommendation is to pick the most appealing one based on price, range and specified accuracy and then do everything you can to ensure a tight and isolated system when you evacuate. Always put the micron gauge as far away from the pump as possible and isolate the pump from the system and gauge for a true reading of depth.

I have seen and used almost every single commercially available micron gauge. Bluevac and JB(69075) do well and so does Inficon. All of them loose accuracy over time and none of them can accurately measure the full range from Atmosphere to deep vacuum. The only gauges that accurately and reliably measure the full range for extended periods of use are the big money bench top ones for lab use and they wouldn't survive in the field.

What you need to know about whatever gauge you use is this. What is the actual range of the sensor? Commercial micron gauges have sensors designed to start reading vacuum only under a certain level. That level could be 20,000 microns 15,000 micron 5,000 micron or even as low as 1,500 microns. Everything the gauge shows you above that is only an estimate and not based on the sensors designed capabilities. If your not sure where you gauge sensors range is, contact the manufacturer or their rep. This piece of information is crucial to using any micron gauge.

My recommendation is to pick the most appealing one based on price, range and specified accuracy and then do everything you can to ensure a tight and isolated system when you evacuate. Always put the micron gauge as far away from the pump as possible and isolate the pump from the system and gauge for a true reading of depth.

The 69075 is a Yellow Jacket not J/B
The OP wants to know about the J/B DV-40 vs the BluVac. Have you used the J/B DV-40 and compared it to anything like the OP?
FWIW you should add a link to your web site on your youtube videos. Had to do the kevin bacon game to find your web site
It did not come up well with a google search either
I saw that thing the other day and it looks nice

I have seen and used almost every single commercially available micron gauge. Bluevac and JB(69075) do well and so does Inficon. All of them loose accuracy over time...

Not entirely true. Yes, since the thermal conductivity sensors are exposed directly to the atmosphere being measure, all TC base micron gauges lose accuracy over time. But, the BluVac is the *only* micron gauge that will both tell you if it is out of calibration (or, if it is contaminated with oil), and that allows you to recalibrate it back to factory specifications simply by placing it in your freezer. No additional hardware or reference gauges required.

Originally Posted by PDImeters

Commercial micron gauges have sensors designed to start reading vacuum only under a certain level. That level could be 20,000 microns 15,000 micron 5,000 micron or even as low as 1,500 microns.

Further, many micron gauges are only rated for accuracy at a particular micron level or narrow micron range, *and* at a specific temperature (normally, room temperature). The BluVacs are rated for full accuracy from 0 to 25,000 microns throughout the entire temperature range of -10C to 50C.

Full disclosure: I am the inventor, designer, and manufacturer of the BluVac/BluVac LTE.

Not entirely true. Yes, since the thermal conductivity sensors are exposed directly to the atmosphere being measure, all TC base micron gauges lose accuracy over time. But, the BluVac is the *only* micron gauge that will both tell you if it is out of calibration (or, if it is contaminated with oil), and that allows you to recalibrate it back to factory specifications simply by placing it in your freezer. No additional hardware or reference gauges required.

JoeyD, thanks for the additional information. Also, let me be upfront here and say that I am certainly not saying anything bad about the Bluevac, your gauge, because I honestly think that it is one of the best available today. I am just trying to offer some insight I have gained about the mysterious world of vacuum and vacuum gauges. I understand how these sensors work and I do believe, please correct me if I am wrong, that all of them eventually will loose their accuracy as they are producing heat and in layman's terms will eventually burn out. The freezer recalibration function of the BlueVac is a brilliant addition and from what I have seen, the BlueVac's life is head and shoulders over most. About that, I have one question. Is there any limit to the number of times that you can "reset" the calibration?

Further, many micron gauges are only rated for accuracy at a particular micron level or narrow micron range, *and* at a specific temperature (normally, room temperature). The BluVacs are rated for full accuracy from 0 to 25,000 microns throughout the entire temperature range of -10C to 50C.

Full disclosure: I am the inventor, designer, and manufacturer of the BluVac/BluVac LTE.

Finally, not to just continue and blow sunshine but I have to say that your did it right with this large of a range. Even with a small leak in a system, it is possible to get down to this range of 25,000 microns so the tech knows that their gauge is working and can then go about finding the leak or other issue when their gauge doesn't look to be dropping quickly. Some of the gauges that don't start accurately registering until the lower ranges (10K micron or 5K microns) make it very difficult to know if it is the system or the tools.

The 69075 is a Yellow Jacket not J/B
The OP wants to know about the J/B DV-40 vs the BluVac. Have you used the J/B DV-40 and compared it to anything like the OP?
FWIW you should add a link to your web site on your youtube videos. Had to do the kevin bacon game to find your web site
It did not come up well with a google search either
I saw that thing the other day and it looks nice

Itsiceman,
First, thanks for the recommendation. I have the web address in the videos but no link on the channel. I will fix that. Also thanks for taking the time to Kevin Bacon my site. I appreciate it. I am working with some stuff to improve my google results but unless you want to just write a big check it takes some time to get the search results you want. Oh the fun that is internet marketing and search engine optimization.

As for the DV-40 Supernova, I have used it. I was not impressed. I got one when they first came out. The first one i bought had some sort of defect right out of the box. The readings were all over the place but my local distributor and JB were great about the replacement. I am a manufacturer so I know that sometimes these things happen and I didn't hold anything against it for this. However, I was just not very impressed with its' accuracy repeatability/reliability. Full disclosure, I never put it to use in a field setting. All testing I did was in a "lab" or factory setting so some of the things that we put it through were a bit unrealistic and I was testing it with a $2,000 NIST certified vacuum gauge. That is how we evaluated all commercial gauges.

Second, thanks for catching my mistake. The 69075 is Yellow Jacket. I brain farted that and didn't catch my slip. That being said, I still think that the YJ 69075 is a pretty okay micron gauge. It is certainly not as compact as the Supernova or the BlueVac and the BlueVac is more accurate and reliable. The price and durability (probably because of the big honking case) of the 69075 made it one of the more preferred gauges I have used. Although, we would regularly (every 6 months or so) line it up with the NIST gauge and identify any drift in the readings. Then I would just add a little sticker to the case with a "+50 microns" or "-100 microns" or whatever the case so that the guys using it would know if they had any additional compensation to factor in their readings.

If I were to buy a gauge for field use, I would probably go with the BluVac for two reasons. 1- It is very accurate, compact, reliable and durable. and 2- The people that you would be dealing with if you bought that gauge would be people like Jim or Bill from TruTech and JoeyD. That is a value that goes beyond what you could normally expect. I prefer to deal with these more personal companies than massive corporations.

But that is just my opinion and I have been wrong once before although I wouldn't admit that to my wife.

...because I honestly think that it is one of the best available today.

A sincere 'thank you' for the compliment!

Originally Posted by PDImeters

...all of them eventually will loose their accuracy as they are producing heat and in layman's terms will eventually burn out.

The BluVac operates at a *very low* temperature compared to other gauges. This is one of the reasons why it has such a long battery life. The sensor will never burn out. But, the sensor can, and will, change slowly over time. Not just from usage and wear, but also due to contaminants settling on the sensor. The self-calibration feature takes these issues into effect and negates them through time.

Originally Posted by PDImeters

Is there any limit to the number of times that you can "reset" the calibration?

There is no limit whatsoever. The BluVac can be recalibrated as often as desired, and each recalibration compensates for any wear or drift of the sensor over time. In fact, *full* factory accuracy is restored via recalibration.

I don't toot my own horn much, but I thought this was worth sharing, especially in this thread.

I was contacted a few days ago by a university student doing post graduate work involving deep vacuum. The lab in which he works has high quality vacuum instrumentation, but he wanted a personal micron gauge of his own. He purchased the UEI DMG100 (the yellow version of the BluVac LTE), and was having problems getting readings less than 100-200 mTorr (microns). We exchanged a few phone calls and emails, and I gave him some suggestions. I received an email from him this morning:

I used your suggestion #2 and I was able to pull down to 0 mtorr -- the
accuracy of your gauge matched the accuracy of our gauge within a few mtorr
-- your gauge performed better than advertised. I appreciate our
communications as you are very astute, clear and helpful. You have designed
an amazing product and I will speak very highly of your gauge.

i have one of those yellow jackets in the case, it cost a million dollars, the fittings all leak and the thing barely stayed calibrated for a year. i just buy a new supco from united two or three times a year, whenever i start feeling uneasy about its accuracy.